Offset rotary printing machine with plate cylinder angular adjustment



July 2. 1968 Filed March 21, 1966 OFF PL OACHIM J' ME PRINT MA IN HAN ROT

CYLINDER ANG R ADJUS ITH NT 3 Sheets-Sheet 1 y 1 1968 HAN -JOACH|M J ME 3,390,632

OFFSET ROT PR ING M C WITH PLATE CYLINDER ULAR ADJ MENT Filed March 21, 1966 3 Sheets-Sheet 2 HIllI!ll|IlllllllllIllllllllllllill- July 2. 1968 HANS-JOACHIM JAHME 3,390,632

OFFSET ROTARY PRINTING MACHINE WITH PLATE CYLINDER ANGULAR ADJUSTMENT Filed March 21. 1966 5 Sheets-Sheet 5- United States Patent 3,390,632 OFFSET ROTARY PRINTING MACHINE WITH PLATE CYLINDER ANGULAR ADJUSTMENT Hans-Joachim Jiihme, Eckernfordestrasse 1, Wieshaden, Germany Filed Mar. 21, 1966, Ser. No. 536,159 3 Claims. (Cl. 101-217) This invention relates to a device or an arrangement for adjusting the angular position of the plate cylinder in a small offset printing machine in which the cylinders are driven by gear wheels of which one is fast with the offset cylinder and the other angularly adjustable on the plate cylinder shaft.

In a known type of printing machine in which the plate cylinder can be angularly adjusted, two gear wheels are mounted side by side on the shaft of the offset cylinder, one of said gear wheels being fast on the shaft and the other rotatably mounted thereon but adapted to be clamped to the gear wheel that is fast on the shaft. The rotatable gear wheel meshes with the gear wheel of the impression cylinder (cf. Deutsches Auslegeschrift Ser. No. 1,777,650). In these known machines the angular position of the plate cylinder cannot be adjusted unless the machine has first been stopped and it is therefore impossible to adjust the lengthwise position of the impression on the paper whilst the machine is in operation.

An object of the present invention is to provide a simple and compact device or arrangement which will permit individual cylinders of the machine to be adjusted angularly in relation to other cylinders from a fixed point of control whilst the machine is in operation. It is envisaged that this device should not take up more space in the axial direction than would be needed to accommodate the thickness of two gear wheels, as is the case of machines fitted with adjusting means for effecting adjustment when the machine has been stopped, thus permitting the present device to be built into existing machines without the necessity of increasing the machine in Width.

According to the invention it is proposed to associate with a first gear wheel which is free on the plate cylinder shaft an intermediate gear wheel with which the first gear wheel is in permanent mesh and to interpose between the intermediate gear wheel and a third gear wheel that is fast on the plate cylinder shaft a shiftable pair of gear wheels meshing with one another and mounted on swivel arms in such manner that one of said pair of gear wheels is movable in the manner of a planet wheel about the centre of the intermediate wheel as its sun wheel and the other of said pair is movable in the manner of a planet wheel about the centre of the said third gear wheel as its associated sun wheel.

An offset printing machine embodying the adjusting device accordinge to the present invention is hereinafter described by way of example, reference being made to the accompanying drawings, wherein:

FIG. 1 is a schematic representation of the complete machine in side elevation,

FIG. 2 is a corresponding view on a larger scale of the three printing cylinders and their associated adjusting gear wheels and control elements, and

FIG. 3 is a section of FIG. 2 taken along line A-B through all the gear wheel contres.

Referring to the drawings, FIG. 1 shows the general disposition of the cylinders of the machine, their drive means and the device consisting of an arrangement of the gear wheels provided for cylinder adjustment.

An impression cylinder 3, which is driven by a belt 2 from a motor 1, carries the paper through the machine and applies the pressure necessary for the formation of the impression. The impression cylinder 3 makes contact ice with an offset printing cylinder 4 which is provided with a soft envelope, usually in the form of a rubber sheet to which a reversed image of the required printing is transferred from a plate cylinder 5 and which in turn again reverses this image in transferring it to the paper on which the image therefore appears as on the plate cylinder 5. The plate cylinder 5, which makes contact with the offset cylinder 4, carries a flexible plate which bears the image that is to be printed. The ink for inking the plate is applied to the same by inking rollers 14. Damping fluid for repelling the ink from the non-printing areasis applied to the plate by the damping rollers 15.

In order to ensure exactly synchronous movement of the three cylinders it is customary to gear them together, the best and most accurate method consisting in associating with each cylinder a gear wheel having a pitch circle which conforms with the cylinder diameter. This is indicated in FIG. 2, where the impression cylinder 3 is associated with a gear wheel Z7, the offset cylinder 4 with a gear wheel Z6 and the plate cylinder 5 with a gear wheel Z4 which latter gear wheel is adjustably connected with a gear wheel Z5.

The gear wheels Z4 and Z5 are provided for the purpose of adjusting the periphery of cylinder 5 in relation to cylinder 4 by adjusting the angular position of the gear wheels. Adjustability of two of the contacting printing cylinders, in the present instance of the plate cylinder 5 in relation to the offset cylinder 4 in the direction of rotation, is requiredin machines of this type for the purpose of regulating the lengthwise position of the impression on the paper.

It will be understood from FIGS. 2 and 3 that the gear where Z5 is free on the shaft of the plate cylinder 5, but in contrast with the known arrangement, means for clamping Z4 and Z5 together are omitted. Instead, the gear wheel Z5 meshes with a gear wheel Z1 on a layshaft 6. as shown in FIG. 2. Moreover, as will be seen from FIG. 2, gear wheel Z1 meshes with gear wheel Z4 which is fast on the shaft of the plate cylinder 5 and hence fast with the plate cylinder 5 itself, through a shiftable pair of gear wheels Z2 and Z3. The centre distance between the two gear wheels Z2 and Z3 of the pair is exactly determined by side links 7. Whereas gear wheel Z2 is mounted on the end of an arm 8 which is pivotable about the axis of gear wheel Z1, gear wheel Z3 is mounted on an arm 9 which is pivota'ble about the axis of gear wheel Z4. The arm 9 can be raised and lowered by an extension attached to a nut 10 on an adjusting screw 11 which is held against axial movernent by bearings in the machine frame. The friction of the nut 10 on the screw 11 locks the nut on the screw 11 in any position to which it has been moved by rotation of a handwheel 12 on the upper end of screw 11. Rotation of the screw 11 causes arm 9 to pivot about the centre of gear wheel Z4 and the side links 7 to pivot the arm 8 about the centre of gear wheel Z1. This action results in gear wheel Z4 and hence the plate cylinder 5, which is nonrota'table in relation to the gear wheel Z4, being rotated in relation to gear wheel Z5 and hence also in relation to gear wheel Z6, which meshes with gear wheel Z5. The simultaneous rotation of the pair of gear wheels Z2 and Z3 further increases the resultant angular displacement, whereas gear wheels Z5 and Z1 remain stationary.

So long as no adjustment of the handwheel 12 is made, the two gear wheels Z4 and Z5 retain their existing relative angular positions without any need to clamp them together because the two gear wheels Z2 and Z3 merely function as intermediate wheels the centres of which are firmly held in position by the bearings of the adjusting screw 11, which is self-locking, and by the arms 8 and 9 and the side links 7. Adjustment of the handwheel 12 can therefore take place whilst the machine is in operation or after it has been stopped.

For a ready understanding of the adjusting action let it be assumed that the process of adjustment takes place whilst the machine is stationary, in other words whilst the gear wheels Z7, Z6, Z and Z1 are kept motionless by the stationary motor whereas the gear wheels Z2, Z3 and Z4 can rotate when the handwheel 12 is turned and the arms 8 and 9 move as gear wheel Z2 rolls on the periphery of gear wheel Z1.

When it is desired to adjust the cylinders, i.e., to adjust the beginning of the printing image on the flexible printing plate to the position on the rubber sheet where the beginning of the offset image is to appear, the two points being shown in FIG. 1 in register, and thereby to adjust the lengthwise position of the impression appearing on the paper, the adjustment screw 11, which is of right-hand screwthread, is rotated clockwise by means of the handwheel 12. The nut is caused to ascend, pivot the arm 9 and simultaneously shift the centre of the wheel Z3 about the centre of gear wheel Z4. The side links 7, which connect the centres of the two gear wheels Z2 and Z3, and which are attached to the arm 8, pivot the arm 8 and there- 'by shift centre of the gear wheel Z2 about the centre 6 of gear wheel Z1.

This shifting of the two gear wheels Z3 and Z2 and the rolling motion of gear wheel Z2 on the periphery of the stationary gear wheel Z1, cause the gear Wheel Z4 to rotate in relation to the gear wheel Z5 and the gear wheel Z6 which meshes with the latter, this relative rotation being equivalent to moving the periphery of the plate cylinder 5 in relation to the periphery of the offset cylinder 4.

If now the machine is so designed that the beginning of the image on the flexible plate and the beginning of the image surface on the rubber sheet are in register when the nut 10 is approximately in the centre of the range of adjustment of the screw 11, peripheries of the printing cylinders can be relatively moved in and contrary to their directions of rotation for the purpose of adjusting the cylinders relatively to one another. The total rotation or angular displacement of gear wheel Z4 is the resultant of four components of motion which are simultaneously when the arm 9 is pivoted.

These components are attributable to (1) The tooth of gear wheel Z3 which is in engagement with gear wheel Z4 and rotates the gear wheel Z4 when the arm 9 is moved through an angle a,

(2) The rolling motion of gear wheel Z2 and Z1 when the arm 9 is pivoted through said angle a, such rolling motion transmitting peripheral motion equal to the length of the gear are corresponding to angle [3 'by means of the gear wheel train Z2 and Z3 to Z4. On the larger gear wheel Z4 the length of this are corresponds to a smaller angle 7 of rotation, namely to are shifted through an angle 'y+oz. This gives rise to a rotation of gear wheel Z4 amounting to (4) The shifting of the side links 7 and the gear wheels Z2 and Z3 about the centre of the gear wheel Z2 in relation to the arm 8 through an angle 7+fi when the arm 9 is pivoted through an angle a. This gives rise to a rotation of gear wheel Z4 amounting to The total rotation of gear wheel Z4 due to these four components is therefore In the embodiment shown in the drawings let it be assumed that The following angular components of motion are then obtained:

Total rotation 72.0

It will thus be seen that the relative angle of rotation results from several rolling and shifting motions of the pair of gear wheels Z2, Z3.

It will be appreciated that the arrangement described with reference to the accompanying drawings could be modified and be within the scope of the invention defined by the appended claims. For example the motor 1 instead of being drivingly connected to the impression cylinder shaft, could be drivingly connected to any other of the shafts carrying the gear train Z1 to Z6. Furthermore, the adjusting means, which in the foregoing example includes a rotatable member having the adjusting screw portion 11, could be arranged to adjust the angular position of the arm 8, in which case the nut member 10 would be mounted on the arm 8 or an extension thereof, instead of on the arm 9, and be in screwthread engagement with the screwthread portion 11.,

I claim:

1. An offset printing machine comprising a frame, impression, offset and plate cylinders, rotary shafts for the respective cylinders carried on parallel axes by said frame, gearing intermeshing and coordinating rotation of said shafts, a motor drivingly connected with one of said shafts, said gearing including respective intermeshing gears fast on the impression and offset cylinder shafts, a free gear on the plate cylinder shaft axis intermeshing with said gear on the offset cylinder shaft, a gear fast on the plate cylinder shaft, an intermediate gear rotatable on a fixed axis, a first arm pivoted on said fixed axis, a first planet gear rotatably supported on a cross-axis on said first arm in constant mesh with and shiftable around said intermediate gear, a second arm pivoted on the plate cylinder shaft axis, a second planet gear rotatably supported on a cross-axis on said second arm in constant mesh with and shifta'ble around said gear fast on the plate cylinder shaft, link means connecting the respective axes of said planet gears and maintaining intermeshing relationship between said planet gears, and adjusting means carried 'by said frame and connected with one of said arms for adjusting the angular position of such arm, adjustment of said angular position causing shifting of said planet gears around their respective gears in mesh therewith, relative angular movement bet-ween said free and fast gears on the plate cylinder axis, and angular adjustment of said plate cylinder relative to said offset cylinder.

2. A machine according to claim 1, wherein said motor is drivingly connected with said impression cylinder shaft, and said adjusting means is connected to said second arm for effecting angular adjustment thereof.

3. A machine according to claim 2, wherein said adjusting means includes a rotatable member having an adjusting screw portion, bearings fixedly carried by said frame permitting rotation of said member and holding said member against axial movement, and a nut member in screwhead engagement with said screw portion and attached to said second arm.

References Cited UNITED STATES PATENTS 2,260,402 10/1944 P-otdevin 101248 6 2,301,379 11/1942 Davis 101--248 2,747,504 5/ 1956 'Fay 101--24-8 FOREIGN PATENTS 662,056 1*1/1951 Great Britain.

ROBERT E. PULFR'EY, Primary Examiner.

J. R. FISHER, Assistant Examiner. 

1. AN OFFSET PRINTING MACHINE COMPRISING A FRAME, IMPRESSION, OFFSET AND PLATE CYLINDERS, ROTARY SHAFTS FOR THE RESPECTIVE CYLINDERS CARRIED ON PARALLEL AXES BY SAID FRAME, GEARING INTERMESHING AND COORDINATING ROTATION OF SAID SHAFTS, A MOTOR DRIVINGLY CONNECTED WITH ONE OF SAID SHAFTS, SAID GEARING INCLUDING RESPECTIVE INTERMESHING GEARS FAST ON THE IMPRESSION AND OFFSET CYLINDER SHAFTS, A FREE GEAR ON THE PLATE CYLINDER SHAFT AXIS INTERMESHING WITH SAID GEAR ON THE OFFSET CYLINDER SHAFT, A GEAR FAST ON THE PLATE CYLINDER SHAFT, AN INTERMEDIATE GEAR ROTATABLE ON A FIXED AXIS, A FIRST ARM PIVOTED ON SAID FIXED AXIS, A FIRST PLANET GEAR ROTATABLY SUPPORTED ON A CROSS-AXIS ON SAID FIRST ARM IN CONSTANT MESH WITH AND SHIFTABLE AROUND SAID INTERMEDIATE GEAR, A SECOND ARM PIVOTED ON THE PLATE CYLINDER SHAFT AXIS, A SECOND PLANET GEAR ROTATABLY SUPPORTED ON A CROSS-AXIS ON SAID SECOND ARM IN CONSTANT MESH WITH AND SHIFTABLE AROUND SAID GEAR FAST ON THE PLATE CYLINDER SHAFT, LINK MEANS CONNECTING THE RESPECTIVE AXES OF SAID PLANET GEARS AND MAINTAINING INTERMESHING RELATIONSHIP BETWEEN SAID PLANET GEARS, AND ADJUSTING MEANS CARRIED BY SAID FRAME AND CONNECTED WITH ONE OF SAID ARMS FOR ADJUSTING THE ANGULAR POSITION OF SUCH ARM, ADJUSTMENT OF SAID ANGULAR POSITION CAUSING SHIFTING OF SAID PLANET GEARS AROUND THEIR RESPECTIVE GEARS IN MESH THEREWITH, RELATIVE ANGULAR MOVEMENT BETWEEN SAID FREE AND FAST GEARS ON THE PLATE CYLINDER AXIS, AND ANGULAR ADJUSTMENT OF SAID PLATE CYLINDER RELATIVE TO SAID OFFSET CYLINDER. 